These are soft chocolate cookies sandwiched with an orange-colored buttercream filling. A super cute Halloween bake that's great to make with kids. Top them with eyeball candies or other thematic extras.
In a large bowl, beat ½ cup granulated sugar, ½ cup packed light brown sugar, ⅓ cup buttermilk, ¼ cup canola oil, and 3 large eggs for 2 minutes, until smooth and slightly lighter in color. Stir in 1 teaspoon vanilla extract.
Sift in 2 cups all-purpose flour, ½ cup Dutch-process cocoa powder, ½ teaspoon baking soda, ½ teaspoon baking powder, and ½ teaspoon salt. Don't overmix. You can have the ingredients measured and sift them directly over the batter when prompted (my choice), or sift them beforehand in a separate bowl.
Cover and refrigerate the batter for 30 minutes to 2 hours.
Preheat the oven to 350°F (180°C).
Scoop the batter onto the prepared baking sheets, leaving room between each mound. Bake for 7 minutes, until the tops spring back when lightly touched. Let cool completely on a wire rack.
Buttercream filling:
In a medium bowl, beat ½ cup unsalted butter, softened, until creamy. Gradually add 2 cups powdered sugar, then 2 tablespoons milk, and beat until light and fluffy, about 2 minutes. The filling should be thick. If it’s too soft, add a couple more tablespoons of powdered sugar.
Add 1-2 drops orange gel food coloring and mix until evenly tinted.
Assemble the whoopie pies:
Spread or pipe a generous amount of buttercream on the flat side of one cookie and top with a second cookie. Add a dab of buttercream to the bottom of edible candy eyes and press them on top of the cookies or into the filling around the edges.
Refrigerate the assembled whoopie pies for about 20 minutes for neater edges and firmer filling, but not much longer.
Notes
Baking time: keep in mind that all ovens and pans are different, even if they look the same or very similar. The baking time in my recipes is as accurate as it can be, but it might take you more or less time. Use a thermometer inside the oven to check that the temperature is right. I recommend you keep track of how your oven works and what tiny details you might need to adjust.Storing: soft cookies can be kept in a single layer in an airtight container for a few days. Separate layers with parchment. You can also freeze them for a month, always well wrapped. Be careful not to smash them. You can also store filled whoopies, but they will turn softer faster due to the moisture of the filling. How do you keep assembled whoopie pies fresh? For the freshest cakes, eat them within a day of making them. After that, keep them in an airtight container. If you fill them as you plan to eat them (a few hours ahead at the most), they will last longer without becoming soggy.